Cell cycle mutants in the budding and fission yeasts have played critical roles in working out how the eukaryotic cell cycle operates and is controlled. The starting point was Lee Hartwell’s 1970s landmark papers describing the first cell division cycle (CDC) mutants in budding yeast. These mutants were blocked at different cell cycle stages and so were unable to complete the cell cycle, thus defining genes necessary for successful cell division. Inspired by Hartwell’s work, I isolated CDC mutants in the very distantly related fission yeast. This started a program of searches for mutants in fission yeast that revealed a range of phenotypes informative about eukaryotic cell cycle control. These included mutants defining genes that were rate-limiting for the onset of mitosis and of the S-phase, that were responsible for there being only one S-phase in each cell cycle, and that ensured that mitosis only took place when S-phase was properly completed. This is a brief account of the discovery of these mutants and how they led to the identification of cyclin-dependent kinases as core to these cell cycle controls.

芽殖酵母和裂殖酵母中的细胞周期突变体在研究真核细胞周期如何运作和控制方面发挥了关键作用。起点是 Lee Hartwell 1970 年代的里程碑式论文，描述了出​​芽酵母中的第一个细胞分裂周期 (CDC) 突变体。这些突变体在不同的细胞周期阶段被阻断，因此无法完成细胞周期，从而定义了成功细胞分裂所必需的基因。受到 Hartwell 工作的启发，我在亲缘关系非常远的裂变酵母中分离出了 CDC 突变体。这启动了一项在裂殖酵母中寻找突变体的计划，该计划揭示了一系列有关真核细胞周期控制的表型信息。这些包括定义基因的突变体，这些基因限制了有丝分裂和 S 期的发生，负责每个细胞周期中只有一个 S 期，并确保只有在 S 期正确完成时才会发生有丝分裂。这是对这些突变体的发现以及它们如何导致鉴定细胞周期蛋白依赖性激酶作为这些细胞周期控制的核心的简要说明。